The present invention relates to a two dimensional drive system, more precisely relates to a two dimensional drive system, which is capable of moving a moving body on a cross point of a couple of shafts by looped members.
An example of conventional two dimensional drive systems having looped members for driving a moving body is disclosed in the U.S. Pat. No. 4,995,277.
In FIG. 3 of the drawing which is prior art, X-belts 100a and 100b are capable of running in an X-direction; Y-belts 102a and 102b are capable of running in a Y-direction perpendicular to the X-direction. The X-belts 100a and 100b are run in the X-direction by a mechanism including a connecting shaft 106a for connecting pulleys 104a and 104b, a connecting shaft 106b for connecting pulleys 104c and 104d, and a motor 108a for rotating the connecting shaft 106a. On the other hand, the Y-belts 102a and 102b are run in the Y-direction by a mechanism including a connecting shaft 106c for connecting pulleys 104e and 104f, a connecting shaft 106d for connecting pulleys 104g and 104h, and a motor 108b for rotating the connecting shaft 106c.
X-moving blocks 110a and 110b are respectively attached to the X-belts 100a and 100b. The X-moving blocks 110a and 110b are capable of moving along X-linear guides 114a and 114b, which are provided on a rectangular frame 112. Y-moving blocks 116a and 116b are respectively attached to the Y-belts 102a and 102b. The Y-moving blocks 116a and 116b are capable of moving along Y-linear guides 118a and 118b, which are provided on the rectangular frame 112.
A moving body 120 is capable of moving on a shaft 122a, whose ends are fixed to the X-moving blocks 110a and 110b, and on a shaft 122b, whose ends are fixed to the Y-moving blocks 116a and 116b. A moving body 120 can be moved in the X-Y directions by running the X-belts 100a and 100b and the Y-belts 102a and 102b.
However, the conventional two dimensional drive system has the following disadvantage.
In the conventional one, as shown in FIG. 3, the connecting shafts 106a, 106b, 106c and 106d are rotatably spanned between gear boxes 124, so that they may bend downward if they are long. If the connecting shafts 106a, 106b, 106c and 106d bend, load of the motors 108a and 108b becomes greater, and high speed movement of the moving body 120 is prevented.